Leaving Group Dependence of the Rates of Halogen-Magnesium Exchange Reactions

作者:Shi Lei*; Chu Yuanyuan; Knochel Paul; Mayr Herbert
来源:Organic Letters, 2012, 14(10): 2602-2605.
DOI:10.1021/ol300906a

摘要

Relative reactivities and absolute rate constants of the reactions of haloarenes with i-PrMgCl center dot LiCl were investigated in THF at 0 degrees C. The rate of the halogen-magnesium exchange decreases in the series Arl > ArBr > ArCl (relative reactivities: 10(11):10(6):1). Preliminary experiments show that the p-tolylsulfinyl group is exchanged slightly faster than iodide, while a tosyl group is exchanged at least 10(4) times more slowly than a bromide.